JP2002312914A - Disk device and head assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently cool a head IC loaded on a suspension. SOLUTION: The disk device includes a housing, an actuator arm rotatably mounted on the housing, a suspension whose base end is fixed to the tip of the actuator arm, a head slider having an electromagnetic transducer loaded on the tip of the suspension, and a head IC loaded on the suspension adjacently to a heads slider. The disk device further includes a heat radiation flexible wiring sheet having a first end fixed to the suspension and thermally connected to the head IC and a second end fixed to the actuator arm and loaded on the suspension and the actuator arm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a disk drive, and more particularly, to a head assembly used in a disk drive.

[0002]

2. Description of the Related Art In recent years, it has been desired to reduce the size and capacity of a magnetic disk device, which is a type of external storage device for a computer. One way to increase the capacity of a magnetic disk device is to increase the number of magnetic disks attached to a spindle motor. With this, the mounting intervals of disks in recent magnetic disk devices have become smaller. I have.

In a recent magnetic disk drive, a contact
A flying magnetic head slider of a start / stop (CSS) type is often used. In the CSS type flying magnetic head slider, when the apparatus is stopped, the magnetic head slider contacts the magnetic disk, and when recording or reproducing information, the air flow generated on the surface of the magnetic disk rotating at high speed causes the magnetic head slider to move slightly with the magnetic disk surface. Float with a gap.

In a CSS type flying magnetic head slider, an electromagnetic transducer (magnetic head element) is incorporated in a magnetic head slider that receives airflow generated on the surface of a magnetic disk, and the magnetic head slider is supported by a suspension. I have.

Accordingly, the magnetic head slider incorporating the electromagnetic transducer contacts the surface of the magnetic disk when the rotation of the magnetic disk is stopped, and the electromagnetic transducer incorporated in the magnetic head slider is supported by the suspension during rotation of the magnetic disk. While moving on the surface of the magnetic disk to record and reproduce information on a predetermined track.

[0006] On the other hand, portable personal computers such as notebook personal computers are often carried, and therefore require high impact resistance. Therefore, a load / unload type magnetic disk device that unloads the head slider from the surface of the magnetic disk when the power is off or in the sleep mode and loads the head slider onto the surface of the magnetic disk when in use is generally employed.

The load / unload type magnetic disk device is provided at the tip of a magnetic head slider on a ramp (inclined portion) of a ramp member provided on an outer peripheral portion of a disk medium when a computer is turned off or in a sleep mode. The magnetic head slider that rides over the corner portion and floats on the magnetic disk with a small gap is separated from the magnetic disk.

Accordingly, when a shock is applied to the computer, the magnetic head slider strikes the magnetic disk,
Damage to the magnetic disk can be avoided.

In either the CSS type magnetic disk device or the load / unload type magnetic disk device, data writing to the magnetic disk and data reading from the magnetic disk are performed by the main print provided in the magnetic disk device. This is performed using a read / write head integrated circuit (head IC) mounted on a wiring board.

That is, when writing data, the head I
A write signal is supplied from C to a magnetic head element via a relay printed wiring board (relay FPC), and the magnetic head element writes data on a magnetic disk.

On the other hand, at the time of data reading, a weak electric signal read by the magnetic head element is supplied to a head IC having a built-in preamplifier via a relay FPC, and the head I
The signal is amplified by C.

[0012]

The data recorded on the magnetic disk is a magnetic head element (electromagnetic transducer).
However, if the head IC is mounted on the main printed wiring board as in the related art, there is a problem that the data transfer speed is low because the magnetic head element and the head IC are very far apart.

[0013] To increase the data transfer speed, a head IC
Is mounted on the suspension adjacent to the magnetic head slider. However, in the configuration in which the head IC is simply mounted on the suspension, the head IC is a high heat-generating element, so that the temperature of the head IC becomes high, the reliability thereof is reduced, and there is a problem that practical use is difficult.

Accordingly, an object of the present invention is to provide a disk device capable of sufficiently radiating heat generated by a head IC mounted on a suspension.

It is another object of the present invention to provide a head assembly capable of efficiently radiating heat generated by a head IC mounted on a suspension.

[0016]

According to one aspect of the present invention, a housing; an actuator arm rotatably mounted within the housing; and a proximal end fixed to a distal end of the actuator arm. A head slider having an electromagnetic transducer mounted on a tip of the suspension; a head IC mounted on the suspension; a head IC fixed to the suspension and thermally connected to the head IC. A disk device having one end and a second end fixed to the actuator arm, and comprising: the suspension and a flexible printed wiring sheet for heat dissipation mounted on the actuator arm. Is done.

The suspension has a printed first wiring pattern for connecting the electromagnetic transducer and the head IC, and a printed second wiring pattern for connecting the head IC to an external circuit.

Preferably, the head IC is connected to the first and second wiring patterns via metal bumps. Preferably, the heat-radiating flexible printed wiring sheet includes an insulating layer made of polyimide or the like, and a copper foil embedded in the insulating layer.

The disk device further includes a relay flexible printed wiring sheet bonded to a side surface of the actuator arm, and the second wiring pattern is connected to the relay flexible printed wiring sheet.

Since the disk device of the present invention has the above-described structure, the head IC mounted on the suspension via the heat-radiating flexible printed wiring sheet
Can be efficiently radiated to the actuator arm, so that the temperature of the head IC is prevented from rising to a predetermined temperature or higher.

According to another aspect of the present invention, a suspension; a head slider having an electromagnetic transducer mounted on the tip of the suspension; a head IC mounted on the suspension; fixed to the suspension; A heat-dissipating flexible printed wiring sheet having a first end thermally connected to the head IC and a second end extending beyond a base end of the suspension and mounted on the suspension; A head assembly is provided, comprising:

Preferably, the suspension has a first printed wiring pattern for connecting the electromagnetic transducer and the head IC, and a second printed wiring pattern for connecting the head IC to an external circuit.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, there is shown a perspective view of a magnetic disk drive with a cover removed. A shaft 4 is fixed to the base 2, and a spindle hub (not shown) that is driven to rotate by a DC motor around the shaft 4 is provided.

The magnetic disks 6 and spacers (not shown) are alternately inserted into the spindle hub, and the disk clamps 8 are fastened to the spindle hub with a plurality of screws 10 so that a plurality of magnetic disks 6 are separated by a predetermined distance. And attached to the spindle hub.

Reference numeral 12 denotes a rotary actuator comprising an actuator arm assembly 14 and a magnetic circuit 16. The actuator arm assembly 14 is rotatably mounted around a shaft 18 fixed to the base 2.

The actuator arm assembly 14 includes
An actuator block 20 rotatably mounted around the shaft 18 via a pair of bearings, a plurality of actuator arms 22 extending in one direction from the actuator block 20, and a head assembly fixed to the distal end of each actuator arm 22 24.

Each head assembly 24 includes a head slider 26 having an electromagnetic transducer (magnetic head element) for writing / reading data to / from the magnetic disk 6;
A suspension 2 having a head slider 26 supported at its distal end and a proximal end fixed to the actuator arm 22
8 is included.

Although not shown in FIG. 1, a head integrated circuit (head IC) is mounted on the suspension 28 adjacent to the head slider 26. A coil (not shown) is supported on the opposite side of the shaft 18 from the actuator arm 22, and the coil is inserted into a gap of the magnetic circuit 16, and a voice coil motor (VCM)
30 are configured.

Reference numeral 32 denotes a main flexible printed wiring board (main FPC) for supplying a write signal to the electromagnetic transducer and extracting a read signal from the electromagnetic transducer, one end of which is fixed to a side surface of the actuator block 20.

Referring to FIG. 2, a perspective view of an actuator arm assembly 14 according to an embodiment of the present invention is shown. A spacer 3 is provided at the tip of the actuator arm 22.
4, the head assembly 24 is fixed.

The head assembly 24 includes a suspension 28 made of stainless steel, and a head slider 26 having an electromagnetic transducer (magnetic head element) is mounted on the tip of the suspension 28. The head slider 2 is further provided on the suspension 28.
6, a head IC 36 is mounted.

On the suspension 28, a printed first wiring pattern 38 for connecting the electromagnetic transducer of the head slider 26 and the head IC 36, and the head IC 3
6 and relay flexible printed wiring sheet (relay FP
C) Printed second wiring pattern 40 connecting to 42)
Are formed. The relay FPC 42 is connected to the main FPC 32 shown in FIG.

Referring to FIG. 3, there is shown a sectional view taken along line 3-3 of FIG. The second wiring pattern 40 including a plurality of lead lines is embedded in an insulating layer 46 such as polyimide.

The second wiring pattern 40 is mainly made of copper,
Gold is deposited over copper over nickel. Similarly, the first wiring pattern 38 is also mainly made of copper, and gold is deposited on copper via nickel.

Referring again to FIG.
8, a flexible printed wiring sheet for heat radiation (FP for heat radiation) across the spacer 34 and the actuator arm 22
C) 44 is adhered.

One end 44a of the heat radiating FPC 44 is arranged below the head IC 36 with an enlarged area. The other end 44b of the heat radiating FPC 44 also has an enlarged area and is adhered to the actuator arm 22.

The heat dissipating FPC 44 has a structure in which a copper foil 50 is embedded in an insulating layer 48 of polyimide or the like as shown in FIG. The heat radiation FPC 44 has dimensions of, for example, 0.4 mm in width, 18 μm in thickness of the copper foil 50, and 12 μm in thickness of each insulating layer 48 except for both ends thereof. The thermal conductivity was 400 W / mK for the copper foil 50 and 0.1 for the insulating layer 48.
5 W / mK.

Referring again to FIG. 3, the head IC 36 is made of a resin 52 such as an epoxy resin, for example.
4 is bonded and mounted. At this time, the second wiring pattern 40 and the electrodes of the head IC 36 are connected by the metal bumps 54 formed of solder or the like.

A gap is formed between the copper foil 50 of the heat radiating FPC 44 and each of the metal bumps 54 to prevent a short circuit between the second wiring pattern 40 and the copper foil 50 of the heat radiating FPC 44. .

Although not shown, the connection between the electrode of the head IC 36 and the first wiring pattern 38 is also shown in FIG.
It has the same structure as the connection structure between the electrode of C36 and the second wiring pattern 40.

When the head IC 36 is driven to read / write data from / to the magnetic disk 6 by the electromagnetic transducer incorporated in the head slider 26, the head IC 36 has a head driving preamplifier, and thus has a high temperature. Heated.

The heat generated by the head IC 36 is transmitted to the heat dissipating FPC 44.
Is transferred to one end 44a of the FPC 44 for heat radiation.
Is transported to the other end 44b by heat conduction, and is radiated to the actuator arm 22 made of, for example, aluminum.

Since the actuator arm 22 has a sufficiently large heat capacity, the heat generated by the head IC 36 through the heat radiating FPC 44 can be efficiently radiated to the actuator arm 22.

In particular, since the heat generated by the head IC 36 can be directly received by the metal bumps 54 and transmitted to the copper foil 50 of the heat radiating FPC 44, good heat radiation efficiency can be ensured. Thereby, the temperature of the head IC 36 can be suppressed to a predetermined temperature or lower, and the operation reliability of the head IC 36 can be ensured.

The heat dissipating FPC 44 is sufficiently thin, and the suspension 28, the spacer 34 and the actuator arm 2
2, the head slider 26 does not receive excessive air resistance during operation of the magnetic disk drive.
It does not interfere with the kinetic characteristics.

Referring to FIG. 5A, there is shown a numerical analysis model diagram for verifying the effect of the present invention. FIG.
(B) is a numerical analysis model diagram of a conventional structure having no heat-dissipating FPC.

The head assembly 55 shown in FIG.
Has a suspension 58. A head slider 56 is mounted on the tip of the suspension 58, and a head IC 60 is mounted adjacent to the head slider 56.

The base end of the suspension 58 is a spacer 6
6 is connected. A wiring pattern 62 is formed on the suspension 58. Further, the head IC 60
The spacer 66 is connected to the heat radiation FPC 64.

The head assembly 55 'having the conventional structure shown in FIG. 5B is obtained by omitting the heat dissipating FPC 64 of the head assembly 55 shown in FIG. 5A.

The heat-dissipating FPC 64 has dimensions of 0.4 mm in width, 18 μm in thickness of copper foil, and 12 μm in thickness of each insulating layer, similarly to the heat-dissipating FPC 44 of the above-described embodiment. Thermal conductivity is 400 W / mK for copper foil and 0.1 for insulating layer.
5 W / mK.

Here, a steady heat-fluid analysis was performed by giving an appropriate heat generation amount to the head IC 60 and a moderate flow rate around the head IC 60. The results are shown in FIGS. 6A and 6B. FIG. 6A shows the temperature distribution of the present invention, and FIG.
(B) shows the temperature distribution of the conventional structure.

When observing FIGS. 6A and 6B,
It is apparent that the temperature of the head IC 60 is reduced when the structure of the present invention is employed as compared with the conventional structure. According to this analysis model, assuming that the thermal resistance between the head IC and the surrounding environment is ΔRja, there was a cooling effect of ΔRja = 50 ° C./W.

The present invention includes the following supplementary notes.

(Supplementary Note 1) A housing; an actuator arm rotatably mounted in the housing; a suspension having a proximal end fixed to a distal end of the actuator arm; and a suspension mounted on a distal end of the suspension. A head slider mounted on the suspension; a first end fixed to the suspension and thermally connected to the head IC; and a first end fixed to the actuator arm. A disk device having a second end, and a heat-radiating flexible printed wiring sheet mounted on the suspension and the actuator arm.

(Supplementary Note 2) The suspension has a printed first wiring pattern for connecting the electromagnetic transducer and the head IC, and a printed second wiring pattern for connecting the head IC to an external circuit. 2. The disk device according to claim 1, wherein

(Supplementary note 3) The disk device according to supplementary note 2, wherein the head IC is connected to the first and second wiring patterns via metal bumps.

(Supplementary note 4) The disk device according to supplementary note 1, wherein the heat-radiating flexible printed wiring sheet includes an insulating layer and a copper foil embedded in the insulating layer.

(Supplementary note 5) The disk device according to supplementary note 4, wherein the heat-radiating flexible printed wiring sheet is adhered to the suspension and the actuator arm.

(Supplementary note 6) The disc according to Supplementary note 2, further comprising a relay flexible printed wiring sheet disposed along a side surface of the actuator arm, wherein the second wiring pattern is connected to the relay flexible printed wiring sheet. apparatus.

(Supplementary Note 7) A suspension; a head slider having an electromagnetic transducer mounted on the tip of the suspension; a head IC mounted on the suspension; A first end connected to the suspension and a second end extending beyond the base end of the suspension, and a heat-radiating flexible printed wiring sheet mounted on the suspension. And head assembly.

(Supplementary Note 8) The suspension has a printed first wiring pattern for connecting the electromagnetic transducer and the head IC, and a printed second wiring pattern for connecting the head IC to an external circuit. 8. The head assembly according to claim 7, wherein:

(Supplementary note 9) The head assembly according to supplementary note 8, wherein the head IC is connected to the first and second wiring patterns via metal bumps.

(Supplementary note 10) The head assembly according to supplementary note 7, wherein the heat-radiating flexible printed wiring sheet includes an insulating layer and a copper foil embedded in the insulating layer.

(Supplementary note 11) The head assembly according to supplementary note 10, wherein the heat-radiating flexible printed wiring sheet is adhered to the suspension.

[0065]

According to the present invention, the head IC mounted on the suspension can be efficiently cooled, since it is configured as described in detail above. As a result, the temperature of the head IC is prevented from rising to a predetermined temperature or higher, and the operation reliability of the head IC can be ensured.

Further, since the head IC can be arranged close to the head slider having the electromagnetic transducer, the data transfer speed can be increased as compared with the configuration in which the head IC is mounted on the main printed wiring board.

[Brief description of the drawings]

FIG. 1 is a perspective view of a magnetic disk drive with a cover removed.

FIG. 2 is a perspective view of an actuator arm assembly according to the embodiment of the present invention.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is a schematic perspective view of a heat radiating FPC.

5 (A) is a numerical analysis model diagram of a head assembly according to the present invention, and FIG. 5 (B) is a numerical analysis model diagram of a head assembly having a conventional structure.

FIG. 6A is a diagram showing a temperature distribution by a numerical analysis model of the present invention, and FIG. 6B is a diagram showing a temperature distribution by a numerical analysis model of a conventional structure.

[Explanation of symbols]

 14 Actuator Arm Assembly 24 Head Assembly 26 Head Slider 28 Suspension 36 Head IC 38 First Wiring Pattern 40 Second Wiring Pattern 42 Relay FPC 44 Heat Dissipating FPC 50 Copper Foil 54 Metal Bump

Claims (5)

[Claims] An actuator arm rotatably mounted in the housing; a suspension having a proximal end fixed to a distal end of the actuator arm; and a suspension mounted on a distal end of the suspension. A head slider having an electromagnetic transducer;
A head IC mounted on the suspension; a first end fixed to the suspension and thermally connected to the head IC, and a second end fixed to the actuator arm; And a heat-radiating flexible printed wiring sheet mounted on the actuator arm. 2. The suspension according to claim 1, further comprising a first printed circuit connecting the electromagnetic transducer and the head IC.
2. The disk device according to claim 1, comprising a wiring pattern and a printed second wiring pattern for connecting the head IC to an external circuit. 3. The disk device according to claim 2, further comprising a relay flexible printed wiring sheet arranged along a side surface of the actuator arm, wherein the second wiring pattern is connected to the relay flexible printed wiring sheet. . 4. A suspension; a head slider having an electromagnetic transducer mounted on a tip of the suspension; a head IC mounted on the suspension; and fixed to the suspension and thermally connected to the head IC. A first end connected thereto and a second end extending beyond a proximal end of the suspension;
And a heat-radiating flexible printed wiring sheet mounted on the suspension. 5. The suspension according to claim 1, further comprising a first printed circuit connecting the electromagnetic transducer and the head IC.
5. The head assembly according to claim 4, further comprising a wiring pattern and a printed second wiring pattern for connecting the head IC to an external circuit.